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EWG's Tap Water Database — 2021 UPDATE

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Perchlorate

Town of Hempstead Water Department

Perchlorate, a component of rocket fuel, occurs both naturally and as a synthetic chemical. Ingested perchlorate interferes with thyroid function. Exposure to perchlorate during pregnancy and childhood can impair cognitive development. Read More.

According to the EPA, perchlorate likely contaminates the water of more than 16 million Americans. Perchlorate interferes with iodine uptake in the thyroid, which can result in reduced thyroid hormones and an impact on metabolism, physical development and cognitive development. Children and developing fetuses are the most at risk from perchlorate contamination.

Perchlorate is the only unregulated contaminant for which the EPA has attempted to set a federal drinking water standard since 1996. However, the agency has yet to propose a draft limit for this contaminant. Perchlorate in drinking water is regulated in Arizona, California, Massachusetts, New Jersey, New York and Texas. California set a public health goal of 1 part per billion for perchlorate in 2015.

Click here to read more about perchlorate.

MORE ABOUT THIS CONTAMINANT

 

119

Samples

0

Samples exceeding legal limit (MCL)

69

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20143.20 ppb3124ND - 5.60 ppb
20152.92 ppb2315ND - 6.00 ppb
20161.98 ppb2214ND - 4.00 ppb
20171.61 ppb1910ND - 4.30 ppb
20180.608 ppb134ND - 2.30 ppb
20190.536 ppb113ND - 2.30 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 1 ppb

The EWG Health Guideline of 1 ppb for perchlorate was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against hormone disruption.

ppb = parts per billion

All test results

Date Lab ID Result
2014-01-091401320-001A4.10 ppb
2014-01-091401320-004A4.80 ppb
2014-02-061402246-003A5.10 ppb
2014-02-061402246-005A4.10 ppb
2014-02-201402992-010A1.10 ppb
2014-02-201402992-009A2.40 ppb
2014-02-201402992-011A4.40 ppb
2014-02-211402A94-005AND
2014-02-211402A94-003A2.70 ppb
2014-02-211402A94-004A1.80 ppb
2014-02-281402G20-002AND
2014-02-281402G20-001AND
2014-02-281402G20-004AND
2014-02-281402G20-003AND
2014-04-111404894-004A4.90 ppb
2014-04-111404894-001A4.60 ppb
2014-05-091405659-004A5.60 ppb
2014-05-091405659-001A4.90 ppb
2014-06-061406465-001A4.50 ppb
2014-06-061406465-004A4.80 ppb
2014-07-031407220-001A4.20 ppb
2014-07-031407220-004A5.20 ppb
2014-07-071407313-002AND
2014-07-071407313-001AND
2014-08-071408406-001A4.40 ppb
2014-08-071408406-004A5.30 ppb
2014-09-051409385-001A4.20 ppb
2014-10-031410224-001A1.70 ppb
2014-11-031411028-004A4.90 ppb
2014-11-031411028-001A4.60 ppb
2014-12-051412408-001A4.90 ppb
2015-01-071501297-010AND
2015-01-071501297-002AND
2015-01-071501297-005A4.60 ppb
2015-01-071501297-001A4.00 ppb
2015-01-071501297-009A1.90 ppb
2015-01-161501975-003A2.60 ppb
2015-01-231501E07-001AND
2015-01-231501E07-002AND
2015-01-231501E07-005A1.90 ppb
2015-02-121502886-004AND
2015-02-121502886-002AND
2015-02-121502886-001AND
2015-02-121502886-003AND
2015-02-271502G98-004A5.60 ppb
2015-02-271502G98-001A5.20 ppb
2015-03-271503J42-001A-POC5.50 ppb
2015-03-271503J42-004A6.00 ppb
2015-04-221504G76-004A5.60 ppb
2015-04-221504G76-001A5.20 ppb
2015-05-081505592-004A4.60 ppb
2015-05-081505592-001A4.60 ppb
2015-06-051506476-001A4.40 ppb
2015-06-051506476-004A5.40 ppb
2016-01-131601866-006PRIND
2016-01-131601866-011A-PRIND
2016-01-131601866-007A-PRIND
2016-01-131601866-004A-PRI3.50 ppb
2016-01-131601866-005A-PRIND
2016-01-131601866-008A-PRIND
2016-01-131601866-003A-PRI2.00 ppb
2016-02-101602827-002AND
2016-02-101602826-003A1.60 ppb
2016-02-101602827-004A4.00 ppb
2016-02-101602827-003A1.000 ppb
2016-02-101602827-001AND
2016-03-111603964-001A3.60 ppb
2016-03-311603P15-002-PRIND
2016-03-311603P15-001-PRI2.20 ppb
2016-04-221604L25-001A3.70 ppb
2016-05-181605G54-001A3.80 ppb
2016-06-161608C67-001A3.30 ppb
2016-07-261607M49-001A3.70 ppb
2016-09-081609564-001A3.60 ppb
2016-11-07703924001-POC3.70 ppb
2016-12-137066850083.80 ppb
2017-01-20709576007ND
2017-01-20709576009ND
2017-01-207095760012.00 ppb
2017-01-207095760023.50 ppb
2017-01-20709576005ND
2017-01-20709576006ND
2017-01-20N-04758ND
2017-01-24709743003-PRIND
2017-01-24709743004-PRIND
2017-01-26709925005-PRI1.20 ppb
2017-01-26709925003-PRIND
2017-02-1370111760013.00 ppb
2017-04-137015807001-POC4.30 ppb
2017-06-2970228060014.10 ppb
2017-07-137024011003-PRIND
2017-07-1370240080012.20 ppb
2017-08-0270259580024.00 ppb
2017-08-097026652001-GEN3.40 ppb
2017-09-217030608002-POC2.90 ppb
2018-01-3070416110032.30 ppb
2018-01-307041611009ND
2018-01-307041611008ND
2018-01-307041611005ND
2018-01-307041611007ND
2018-01-3070416110061.60 ppb
2018-01-307041611004ND
2018-02-027041918002ND
2018-02-027041918001ND
2018-05-117051444001-POCND
2018-07-207058919001-PRI2.30 ppb
2018-07-207058919002ND
2018-07-2070589190031.70 ppb
2019-01-297077777004ND
2019-01-297077777006ND
2019-01-297077777005ND
2019-01-297077777007ND
2019-01-2970777770032.10 ppb
2019-01-317078022001ND
2019-03-287083792001ND
2019-03-287083792006ND
2019-03-2870837920041.50 ppb
2019-03-2870837920052.30 ppb
2019-10-3070110165001ND